Presentation Information
[15a-S2_202-7]Investigation of Molecular Ion Formation under Water and Argon Cluster Irradiation
〇Kousuke Moritani1, Taisei Toku1, Norio Inui1 (1.Univ. of Hyogo)
Keywords:
GCIB,ToF-SIMS,water cluster
Gas cluster ion beam secondary ion mass spectrometry (GCIB-SIMS) is a powerful technique for the analysis of biological and organic materials, since molecular ions and high-mass fragments can be detected with reduced fragmentation. In this study, the molecular ion formation process under water and argon cluster irradiation was investigated. Thin films of benzylpyridinium, a well-known thermometer ion, were irradiated with size-selected argon and heavy water gas cluster ions at an acceleration energy of 5 keV, and the energy per constituent (E/n) was varied from 1.67 to 9.62 eV. Under heavy water cluster irradiation, the molecular ion yield increased significantly in the low E/n region below 3 eV, and molecular ions with attached water molecules were observed. At higher E/n, the molecular ion yield decreased and became comparable to that obtained with argon clusters. The internal energy of molecular ions was estimated using the survival yield method, and the desorption and formation mechanisms of molecular ions under water cluster irradiation are discussed.